leetcode自由刷题

说明

• 代码主要由C/C++或者Go语言编写，少量python，部分题目为SQL或者shell脚本操作，可根据文件后缀判断；
• 全部代码解法均为时间最优解，在某些题的代码中，包含多个可AC方法，最终也只采用时间/空间最优解；
• 每个题单独创建以题名为命名的文件夹，内含有源码与单元测试代码，均通过测试；
• 某些题目未给出时间复杂度，其原因多在于存在回溯操作，难以正确估计实际时间复杂度；
• 若题目对空间复杂度有明确要求，例如O(1)，所给代码均按照要求实现。

C 补充

• 代码使用 C11 标准，构建工具使用 CMake ，推荐使用 Clion 作为IDE，导入工程目录为：leetcode/leetcode-c，已经配置好 CMakeLists.txt 脚本；
• 某些低版本编译器可能无法编译， 平台+编译器推荐组合如下：
  • Linux(推荐)：GCC 或 Clang
  • Windows(可用)：Visual Studio(MSVC) 16.8版本以上 + Windows 10 SDK (10.0.20348.0) 版本 2104 以上)
  • macOS(可用)：Apple Clang 或 GCC
• C单元测试采用 ThrowTheSwitch/Unity ，性能测试采用 sheredom/ubench.h，在CMake构建中会拉取最新源码，需要环境自带Git；
• 哈希表采用 uthash 项目中的uthash.h，在CMake构建中会拉取最新源码；
• 将检测编译器是否支持 AddressSanitizer 内存检查功能，若支持将启用。

C++ 补充

• 代码使用 C++ 14 标准，构建工具使用 CMake ，推荐使用 Clion 作为IDE，导入工程目录为：leetcode/leetcode-cpp，已经配置好 CMakeLists.txt 脚本；
• 某些低版本编译器可能无法编译， 平台+编译器推荐组合如下：
  • Linux(推荐)：GCC 或 Clang
  • Windows(可用)：Visual Studio(MSVC) 16.8版本以上
  • macOS(可用)：Apple Clang 或 GCC
• C++单元测试采用 Google Test ，性能测试采用 Google Benchmark ，二者在CMake构建中会拉取最新源码，需要环境自带Git。
• 将检测编译器是否支持 AddressSanitizer 内存检查功能，若支持将启用。

Golang 补充

• 使用mod管理包，推荐使用 Goland 作为IDE，导入工程目录为：leetcode/leetcode-go ；
• Golang自动化测试使用自带test命令，包括单元测试和性能测试。

Python 补充

• 基于 python3.6 及以上版本，推荐使用 Pycharm 作为IDE，导入工程目录为：leetcode/leetcode-python ；
• python单元测试采用标准库uniitest，也推荐使用pytest进行全量测试；

SQL 补充

• SQL语法适用于MySQL数据库（版本8.0以上）;
• 所有的SQL操作均在名为leetcode的数据库中进行。

Shell补充

• Shell 使用 Bash (Bourne Again shell)

汇总表

编号	题目	代码文件	时间复杂度	简述	空间复杂度
1	Two Sum	two-sum.go	O(n)	哈希Map
2	Add Two Numbers	add-two-numbers.go	O(n)	单向链表
3	Longest Substring Without Repeating Characters	longest-substring-without-repeating-characters.go	O(n)	DP优化
4	Median of Two Sorted Arrays	median-of-two-sorted-arrays.go	O(log(min(m,n)))	参考Grandyang博客
5	Longest Palindromic Substring	longest-palindromic-substring.go	O(n)	manacher算法
6	ZigZag Conversion	zigzag-conversion.go	O(n)	规律总结
7	Reverse Integer	reverse-integer.go	O(n)	strconv.Itoa()+strconv.Atoi()实现
8	String to Integer (atoi)	string-to-integer-atoi.go		正则匹配
9	Palindrome Number	palindrome-number.go	O(n/2)	strconv.Itoa()实现
10	Regular Expression Matching	regular-expression-matching.go	O(n*m)	DP
11	Container With Most Water	container-with-most-water.go	O(n)	two-pointer算法
12	Integer to Roman	integer-to-roman.go	O(n)	打表
13	Roman to Integer	roman-to-integer.go	O(n)	switch-case
14	Longest Common Prefix	longest-common-prefix.go	O(n*m)	if模拟
15	3Sum	3sum.go	O(n^2)	two-pointer
16	3Sum Closest	3sum-closest.go	O(n^2)	two-pointer
17	Letter Combinations of a Phone Number	letter-combinations-of-a-phone-number.go	O(4^n)	循环
18	4Sum	4sum.go	O(n^3)	two-pointer
19	Remove Nth Node From End of List	remove-nth-node-from-end-of-list.go	O(n)	循环数组(one pass)
20	Valid Parentheses	valid-parentheses.go	O(n)	栈
21	Merge Two Sorted Lists	merge-two-sorted-lists.go	O(m+n)	递归
22	Generate Parentheses	generate-parentheses.go	O(2^n)	递归
23	Merge k Sorted Lists	merge-k-sorted-lists.go	O(log(n)*m)	分治
24	Swap Nodes in Pairs	swap-nodes-in-pairs.go	O(n)	单链表交换节点
25	Reverse Nodes in k-Group	reverse-nodes-in-k-group.go	O(n)	记录前驱+后驱节点	O(1)
26	Remove Duplicates from Sorted Array	remove-duplicates-from-sorted-array.go	O(n)	slice传参：带地址的结构体值	O(1)
27	Remove Element	remove-element.go	O(n)	单链表删除操作	O(1)
28	Implement strStr()	implement-strstr.go	O(n+m)	KMP算法
29	Divide Two Integers	divide-two-integers.go	O(log(n))	位操作实现除法
30	Substring with Concatenation of All Words	substring-with-concatenation-of-all-words.go	O(n)	滑动窗口+HashMap
31	Next Permutation	next-permutation_test.go	O(n)	参考C++ std::next_next_permutation	O(1)
32	Longest Valid Parentheses	longest-valid-parentheses.go	O(n)	栈
33	Search in Rotated Sorted Array	search-in-rotated-sorted-array.go	O(log(n))	二分查找
34	Find First and Last Position of Element in Sorted Array	find-first-and-last-position-of-element-in-sorted-array.go	O(log(n))	二分查找
35	Search Insert Position	search-insert-position.go	O(log(n))	二分查找
36	Valid Sudoku	valid-sudoku.go	O(n^2)	位操作判重
37	Sudoku Solver	sudoku-solver.go		DanceLink X算法
38	Count and Say	count-and-say.go		递归 + strings.Builder加速
39	Combination Sum	combination-sum.go		DFS
40	Combination Sum II	combination-sum-ii.go		DFS+剪枝
41	First Missing Positive	first-missing-positive.go	O(n)	判 nums[idx]=nums[nums[idx]-1]	O(1)
42	Trapping Rain Water	trapping-rain-water.go	O(n)	不下降子数组
43	Multiply Strings	multiply-strings.go	O(n+m)	模拟乘法
44	Wildcard Matching	wildcard-matching.go	O(n)	双指针
45	Jump Game II	jump-game-ii.go	O(n)	二次扩展	O(1)
46	Permutations	permutations.go	O(n!)	全排列
47	Permutations II	permutations-ii.go		不重复全排列
48	Rotate Image	rotate-image.go	O(n^2)	图像处理：旋转变换矩阵	O(1)
49	Group Anagrams	group-anagrams.go	O(m*n)	HashMap+桶排序思想
50	Pow(x, n)	powx-n.go	O(log(n))	快速幂
51	N-Queens	n-queens.go	O(n^n)	回溯+位操作加速
52	N-Queens II	n-queens-ii.go	O(1)	打表	O(1)
53	Maximum Subarray	maximum-subarray.go	O(n)	最大和子串	O(1)
54	Spiral Matrix	spiral-matrix.go	O(m*n)	模拟
55	Jump Game	jump-game.go	O(n)	二次扩展	O(1)
56	Merge Intervals	merge-intervals.go	O(nlog(n))	slice排序
57	Insert Interval	insert-interval.go	O(n)	模拟
58	Length of Last Word	length-of-last-word.go	O(n)	找首次非后导空格符
59	Spiral Matrix II	spiral-matrix-ii.go	O(n^2)	模拟
60	Permutation Sequence	permutation-sequence.go	O(n)	规律+递归
61	Rotate List	rotate-list.go	O(n)	旋转单链表	O(1)
62	Unique Paths	unique-paths.go	O(m*n)	DP+滚动数组	O(min(m,n))
63	Unique Paths II	unique-paths-ii.go	O(m*n)	DP+滚动数组	O(min(m,n))
64	Minimum Path Sum	minimum-path-sum.go	O(m*n)	DP
65	Valid Number	valid-number.go	O(n)	确定有限状态自动机DFA	O(1)
66	Plus One	plus-one.go	O(n)	模拟进位
67	Add Binary	add-binary.go	O(n)	模拟二进制加法
68	Text Justification	text-justification.go	O(m*n)	格式控制
69	Sqrt(x)	sqrtx.go	O(log(n))	二叉搜索树	O(1)
70	Climbing Stairs	climbing-stairs.go	O(n)	斐波那契数列(递推)	O(1)
71	Simplify Path	simplify-path.go simplify-path.cpp	O(n)	栈	O(n)
72	Edit Distance	edit-distance.go	O(m*n)	编辑距离DP	O(m*n)
73	Set Matrix Zeroes	set-matrix-zeroes.go	O(m*n)	表头标记	O(1)
74	Search a 2D Matrix	search-a-2d-matrix.go	O(log(m*n))	二分查找	O(1)
75	Sort Colors	sort-colors.go	O(n)	桶排序	O(1)
76	Minimum Window Substring	minimum-window-substring.go	O(n)	滑动窗口+数组代替HashMap优化
77	Combinations	combinations.go	O((n-k)!)	排列：递归
78	Subsets	subsets.go	O(2^n)	全子集：递归
79	Word Search	word-search.go		DFS
80	Remove Duplicates from Sorted Array II	remove-duplicates-from-sorted-array-ii.go	O(n)	遍历	O(1)
81	Search in Rotated Sorted Array II	search-in-rotated-sorted-array-ii.go	O(n)	二分搜索
82	Remove Duplicates from Sorted List II	remove-duplicates-from-sorted-list-ii.go	O(n)	维护单链表preNode
83	Remove Duplicates from Sorted List	remove-duplicates-from-sorted-list.go	O(n)	保证pNode.Val != pNode.Next.Val
84	Largest Rectangle in Histogram	largest-rectangle-in-histogram.go	O(n)	单调栈
85	Maximal Rectangle	maximal-rectangle.go	O(m*n)	转换为直方图求最大矩形：单调栈
86	Partition List	partition-list.go	O(n)	双指针	O(1)
87	Scramble String	scramble-string.go		分治
88	Merge Sorted Array	merge-sorted-array.go	O(n)	从后向前遍历
89	Gray Code	gray-code.go gray-code.cpp	O(2^n)	格雷码
90	Subsets II	subsets-ii.go	O(2^n)	去重全子集：递归
91	Decode Ways	decode-ways.go	O(n)	斐波那契变形+滚动数组	O(1)
92	Reverse Linked List II	reverse-linked-list-ii.go	O(n)	单链表部分翻转	O(1)
93	Restore IP Addresses	restore-ip-addresses.go		DFS
94	Binary Tree Inorder Traversal	binary-tree-inorder-traversal.go	O(N)	中序遍历(Morris遍历)	O(1)
95	Unique Binary Search Trees II	unique-binary-search-trees-ii.go		异构二叉搜索树
96	Unique Binary Search Trees	unique-binary-search-trees.go	O(1)	卡特兰数	O(1)
97	Interleaving String	interleaving-string.go	O(mn)	DP+滚动数组+状态压缩	O(1)
98	Validate Binary Search Tree	validate-binary-search-tree.go	O(n)	判定二叉搜索树
99	Recover Binary Search Tree	recover-binary-search-tree.go	O(n)	Morris中序遍历	O(1)
100	Same Tree	same-tree.go	O(n)	树的遍历
101	Symmetric Tree	symmetric-tree.go	O(n)	相同层子树递归比较	O(n)
102	Binary Tree Level Order Traversal	binary-tree-level-order-traversal.go	O(n)	二叉树层级遍历	O(log(n))
103	Binary Tree Zigzag Level Order Traversal	binary-tree-zigzag-level-order-traversal.go	O(n)	二叉树层级遍历	O(log(n))
104	Maximum Depth of Binary Tree	maximum-depth-of-binary-tree.go	O(n)	DFS+BFS	O(n)
105	Construct Binary Tree from Preorder and Inorder Traversal	construct-binary-tree-from-preorder-and-inorder-traversal.cpp	O(n)	先序+中序构造二叉树	O(n)
106	Construct Binary Tree from Inorder and Postorder Traversal	construct-binary-tree-from-inorder-and-postorder-traversal.cpp	O(n)	中序+后序构造二叉树	O(n)
107	Binary Tree Level Order Traversal II	binary-tree-level-order-traversal-ii.cpp	O(n)	BFS	O(n)
108	Convert Sorted Array to Binary Search Tree	convert-sorted-array-to-binary-search-tree.cpp	O(n)	有序数组转BTS:分治	O(n)
109	Convert Sorted List to Binary Search Tree	convert-sorted-list-to-binary-search-tree.cpp	O(n)	有序链表转BTS:分治	O(n)
110	Balanced Binary Tree	balanced-binary-tree.cpp	O(n)	判平衡二叉树：递归
111	Minimum Depth of Binary Tree	minimum-depth-of-binary-tree.cpp	O(n)	二叉树最小深度：DFS+剪枝
112	Path Sum	path-sum.cpp	O(n)	DFS遍历树	O(1)
113	Path Sum II	path-sum-ii.cpp	O(n)	DFS遍历树+记录路径	O(n)
114	Flatten Binary Tree to Linked List	flatten-binary-tree-to-linked-list.cpp	O(n)	转换二叉树为先序链表：直接修改树	O(1)
115	Distinct Subsequences	distinct-subsequences.cpp	O(n^2)	DP+滚动数组	O(n)
116	Populating Next Right Pointers in Each Node	populating-next-right-pointers-in-each-node.cpp	O(n)	二叉树的DFS	O(1)
117	Populating Next Right Pointers in Each Node II	populating-next-right-pointers-in-each-node-ii.cpp	O(n)	二叉树的DFS：根右左	O(1)
118	Pascal's Triangle	pascals-triangle.cpp	O(n^2)	构建帕斯卡三角	O(n^2)
119	Pascal's Triangle II	pascals-triangle-ii.cpp	O(n^2)	构建帕斯卡三角单行	O(n)
120	Triangle	triangle.cpp	O(n^2)	DP+滚动数组	O(n)
121	Best Time to Buy and Sell Stock	best-time-to-buy-and-sell-stock.cpp	O(n)	维护前驱最小	O(1)
122	Best Time to Buy and Sell Stock II	best-time-to-buy-and-sell-stock-ii.cpp	O(n)	贪心	O(1)
123	Best Time to Buy and Sell Stock III	best-time-to-buy-and-sell-stock-iii.cpp	O(n)	DP	O(1)
124	Binary Tree Maximum Path Sum	binary-tree-maximum-path-sum.cpp	O(n)	DFS	O(n)
125	Valid Palindrome	valid-palindrome.cpp	O(n)	判断回文字串	O(1)
126	Word Ladder II	word-ladder-ii.cpp	O(n*26^(l/2))	双向BFS+DFS	O(k*n)
127	Word Ladder	word-ladder.cpp	O(n*26^(l/2))	双向BFS	O(n)
128	Longest Consecutive Sequence	longest-consecutive-sequence.cpp	O(n)	HashMap	O(n)
129	Sum Root to Leaf Numbers	sum-root-to-leaf-numbers.cpp	O(2^n)	二叉树深度遍历	O(1)
130	Surrounded Regions	longest-consecutive-sequence.cpp	O(m*n)	DFS地图	O(1)
131	Palindrome Partitioning	palindrome-partitioning.cpp	O(2^n)	DFS+DP	O(2^n)
132	Palindrome Partitioning II	palindrome-partitioning-ii.cpp	O(n^2)	DP	O(n)
133	Clone Graph	clone-graph.cpp	O(VE)	深拷贝：无向图	O(VE)
134	Gas Station	gas-station.cpp	O(n)	贪心	O(1)
135	Candy	candy.cpp	O(n)	贪心	O(n)
136	Single Number	single-number.cpp	O(n)	异或判重	O(1)
137	Single Number II	single-number-ii.cpp	O(n)	位操作模拟三进制	O(1)
138	Copy List with Random Pointer	copy-list-with-random-pointer.cpp	O(n)	深拷贝：原节点后拷贝新节点	O(1)
139	Word Break	word-break.cpp	O(n^2)	HashMap+DP	O(n)
140	Word Break II	word-break-ii.cpp		DFS+HashSet	O(n)
141	Linked List Cycle	linked-list-cycle.go linked-list-cycle.cpp	O(n)	链表判环：快慢指针	O(1)
142	Linked List Cycle II	linked-list-cycle-ii.cpp	O(n)	链表环起点：快慢指针	O(1)
143	Reorder List	reorder-list.cpp	O(n)	链表重排序	O(1)
145	Binary Tree Postorder Traversal	binary-tree-postorder-traversal.cpp	O(n)	二叉树后序遍历	O(n)
146	LRU Cache	lru-cache.cpp	O(1)	双向链表+HashMap实现LRU	O(n)
147	Insertion Sort List	insertion-sort-list.cpp	O(n^2)	单链表插入排序	O(1)
148	Sort List	sort-list.cpp	O(nlog(n))	单链表归并排序	O(1)
149	Max Points on a Line	max-points-on-a-line.cpp	O(n^2)	三点枚举优化/斜率HashMap	O(n)
150	Evaluate Reverse Polish Notation	evaluate-reverse-polish-notation.cpp	O(n)	后缀表达式（逆波兰式）求值	O(n)
151	Reverse Words in a String	reverse-words-in-a-string.cpp	O(n)	单词翻转	O(1)
152	Maximum Product Subarray	maximum-product-subarray.cpp	O(n)	DP	O(1)
153	Find Minimum in Rotated Sorted Array	find-minimum-in-rotated-sorted-array.c	O(log(n))	二分查找	O(log(n))
154	Find Minimum in Rotated Sorted Array II	find-minimum-in-rotated-sorted-array-ii.c	O(n)	二分查找	O(n)
155	Min Stack	min-stack.cpp	O(1)	最小栈	O(n)
160	Intersection of Two Linked Lists	intersection-of-two-linked-lists.cpp	O(n)	反转链表	O(1)
162	Find Peak Element	find-peak-element.cpp	O(log(n))	二分查找	O(1)
165	Compare Version Numbers	compare-version-numbers.cpp	O(n)	字符串分割	O(n)
166	Fraction to Recurring Decimal	fraction-to-recurring-decimal.cpp	O(n)	长除法	O(n)
167	Two Sum II - Input array is sorted	two-sum-ii-input-array-is-sorted.cpp	O(n)	two-pointer	O(1)
168	Excel Sheet Column Title	excel-sheet-column-title.cpp	O(n)	进制转换	O(1)
169	Majority Element	majority-element.cpp	O(n)	摩尔投票算法	O(1)
171	Excel Sheet Column Number	excel-sheet-column-number.cpp	O(n)	进制转换	O(1)
172	Factorial Trailing Zeroes	factorial-trailing-zeroes.cpp	O(1)	阶乘末尾0个数	O(1)
173	Binary Search Tree Iterator	binary-search-tree-iterator.cpp	O(1)	中序遍历非递归实现	O(log(n))
174	Dungeon Game	dungeon-game.c	O(m*n)	DP+滚动数组	O(min(m,n))
175	Combine Two Tables	combine-two-tables.sql		左连接
176	Second Highest Salary	second-highest-salary.sql		max()函数
177	Nth Highest Salary	nth-highest-salary.sql		dense_rank()函数
178	Rank Scores	rank-scores.sql		dense_rank()函数
179	Largest Number	largest-number.c	O(nlog(n))	字符串排序	O(n)
180	Consecutive Numbers	consecutive-numbers.sql		lag()/lead()函数
181	Employees Earning More Than Their Managers	employees-earning-more-than-their-managers.sql		自连接
182	Duplicate Emails	duplicate-emails.sql		查找重复元素
183	Customers Who Never Order	customers-who-never-order.sql		左连接不包含内连接
184	Department Highest Salary	department-highest-salary.sql		左连接+子查询
185	Department Top Three Salaries	department-top-three-salaries.sql		窗口函数: dense_rank()
187	Repeated DNA Sequences	repeated-dna-sequences.c	O(n)	hashset+位压缩	O(n)
189	Rotate Array	rotate-array.cpp	O(n)	递归	O(1)
190	Reverse Bits	reverse-bits.cpp	O(1)	《Hacker's Delight》图 7-1	O(1)
191	umber of 1 Bits	number-of-1-bits.cpp	O(1)	《Hacker's Delight》图 5-2	O(1)
192	Word Frequency	word-frequency.sh	O(nlog(n))	declare + sed + sort命令	O(n)
193	Valid Phone Numbers	valid-phone-numbers.sh		grep命令+正则
195	Tenth Line	tenth-line.sh		sed命令
196	Delete Duplicate Emails	delete-duplicate-emails.sql		with+rank()
197	Rising Temperature	rising-temperature.sql		自连接
198	House Robber	house-robber.cpp	O(n)	DP	O(1)
199	Binary Tree Right Side View	binary-tree-right-side-view.cpp	O(n)	BFS	O(n)
200	Number of Islands	number-of-islands.cpp	O(m*n)	地图DFS	O(m*n)
201	Bitwise AND of Numbers Range	bitwise-and-of-numbers-range.cpp	O(log(n))	位操作	O(1)
202	Happy Number	happy-number.c		模拟	O(1)
203	Remove Linked List Elements	remove-linked-list-elements.c	O(n)	遍历	O(1)
204	Count Primes	count-primes.c	O(n)	欧拉筛素数法	O(n)
205	Isomorphic Strings	isomorphic-strings.cpp	O(n)	字典	O(1)
206	Reverse Linked List	reverse-linked-list.cpp	O(n)	单链翻转	O(1)
207	Course Schedule	course-schedule.cpp	O(V+E)	拓扑排序	O(V+E)
208	Implement Trie (Prefix Tree)	implement-trie-prefix-tree.c	O(n)	前缀树	O(26^n)
209	Minimum Size Subarray Sum	minimum-size-subarray-sum.c	O(n)	滑动窗口	O(1)
210	course-schedule-ii	course-schedule-ii.cpp	O(V+E)	拓扑排序	O(V+E)
211	Design Add and Search Words Data Structure	design-add-and-search-words-data-structure.c	O(n)	前缀树	O(26^n)
215	Kth Largest Element in an Array	kth-largest-element-in-an-array.cpp	O(n)	std::nth_element	O(1)
217	Contains Duplicate	contains-duplicate.c	O(n)	hashset	O(n)
219	Contains Duplicate II	contains-duplicate-ii.cpp	O(n)	滑动窗口+hashset	O(n)
221	Maximal Square	maximal-square.cpp	O(m*n)	DP+状态压缩	O(n)
223	Rectangle Area	rectangle-area.cpp	O(1)	矩形面积	O(1)
224	Basic Calculator	basic-calculator.cpp	O(n)	表达式求值	O(n)
227	Basic Calculator II	basic-calculator-ii.cpp	O(n)	表达式求值	O(n)
228	Summary Ranges	summary_ranges.py	O(n)	双指针	O(n)
231	Power of Two	power_of_two.py	O(1)	位运算	O(1)
233	Number of Digit One	number-of-digit-one.c	O(log10(n))	数学推导+递归	O(log10(n))
234	Palindrome Linked List	palindrome-linked-list.c	O(n)	反转链表+双指针比较	O(1)
236	Ugly Number	ugly_number.py	O(log(n))	素数	O(1)
237	Delete Node in a Linked List	delete-node-in-a-linked-list.c	O(1)	链表	O(1)
239	Sliding Window Maximum	sliding-window-maximum.c	O(n)	单调队列	O(n)
240	Search a 2D Matrix II	search-a-2d-matrix-ii.cpp	O(m+n)	二叉查找树	O(1)
242	Valid Anagram	valid-anagram.cpp	O(n)	字符字典	O(1)
258	Add Digits	add_digits.py	O(1)	树根	O(1)
260	Single Number III	single-number-iii.c	O(n)	异或+分组	O(1)
264	Ugly Number II	ugly-number-ii.c	O(n)	DP	O(n)
268	Missing Number	missing-number.c	O(n)	等差数列求和	O(1)
274	H-Index	h-index.cpp	O(n)	桶排序	O(n)
275	H-Index II	h-index-ii.cpp	O(log(n))	二分	O(n)
278	First Bad Version	first-bad-version-test.cpp	O(log(n))	二分	O(1)
282	Expression Add Operators	expression-add-operators.c	O(4^n)	DFS	O(n)
283	Move Zeroes	move-zeroes.cpp	O(n)	交换操作	O(1)
287	find-the-duplicate-number	find-the-duplicate-number.cpp	O(n)	快慢指针	O(1)
289	Game of Life	game-of-life.c	O(m*n)	遍历+位操作	O(1)
290	Word Pattern	word-pattern.cpp	O(n)	map + split	O(1)
292	Nim Game	nim-game.c	O(1)	博弈论	O(1)
293	Sliding Window Maximum	sliding-window-maximum.c	O(n)	双向链表+单调队列	O(n)
295	Find Median from Data Stream	find-median-from-data-stream.cpp	O(nlog(n))	优先队列/堆	O(n)
299	Bulls and Cows	bulls-and-cows.cpp	O(n)	遍历	O(n)
304	Range Sum Query 2D - Immutable	range_sum_query_2d_immutable.py	O(m*n)	动态规划	O(m*n)
326	Power of Three	power_of_three.py	O(1)	质数	O(1)
352	Data Stream as Disjoint Intervals	data-stream-as-disjoint-intervals.c	O(n)	桶遍历	O(n)
365	Water and Jug Problem	water-and-jug-problem.c	O(log(n))	gcd	O(1)
367	Valid Perfect Square	valid-perfect-square.cpp	O(log4(n))	二分查找	O(1)
372	Super Pow	super-pow.cpp	O(n)	快速幂	O(1)
380	Insert Delete GetRandom O(1)	insert-delete-getrandom-o1.c	O(1)	HashMap	O(n)
384	Shuffle an Array	shuffle-an-array.c	O(n)	Fisher–Yates shuffle 洗牌算法	O(n)
393	UTF-8 Validation	utf-8-validation.c	O(n)	UTF-8编码验证	O(1)
397	Integer Replacement	integer-replacement.c	O(log(n))	贪心	O(1)
400	Nth Digit	nth-digit.cpp	O(log10(n))	递归	O(log10(n))
406	Queue Reconstruction by Height	queue-reconstruction-by-height.c	O(n^2)	快速排序+插入	O(n)
416	Partition Equal Subset Sum	partition-equal-subset-sum.cpp	O(n*sum/2)	01背包	O(sum/2)
429	N-ary Tree Level Order Traversal	n-ary-tree-level-order-traversal.cpp	O(n)	广度优先遍历	O(n)
434	Number of Segments in a String	number-of-segments-in-a-string.c	O(n)	遍历	O(1)
435	Non-overlapping Intervals	non-overlapping-intervals.c	O(nlog(n))	贪心	O(nlog(n))
436	Find Right Interval	find-right-interval.c	O(nlog(n))	排序+二分查找	O(n)
437	Path Sum III	path-sum-iii.c	O(n)	前缀和+HashMap	O(n)
447	Number of Boomerangs	number-of-boomerangs.c	O(n^2)	HashMap	O(n)
451	Sort Characters By Frequency	sort-characters-by-frequency.cpp	O(n)	桶排序	O(n)
454	4Sum II	4sum-ii.cpp	O(n^2)	HashMap	O(n^2)
460	LFU Cache	lfu-cache.cpp	O(1)	双向链表+双HashMap实现LFU	O(n)
463	Island Perimeter	island-perimeter.cpp	O(m*n)	遍历	O(1)
473	Matchsticks to Square	matchsticks-to-square.c		DFS	O(n)
475	Heaters	heaters.cpp	O(nlog(n))	排序	O(1)
478	Generate Random Point in a Circle	generate-random-point-in-a-circle.cpp	O(1)	极坐标	O(1)
498	Diagonal Traverse	diagonal-traverse.cpp	O(m*n)	模拟	O(1)
513	Find Bottom Left Tree Value	find-bottom-left-tree-value.c	O(n)	递归	O(log(n))
528	Random Pick with Weight	random-pick-with-weight.c	O(log(n))	前缀和数组+二分查找	O(n)
537	Complex Number Multiplication	complex-number-multiplication.go	O(n)	复数相乘	O(1)
540	Single Element in a Sorted Array	single-element-in-a-sorted-array.cpp	O(log(n))	二分查找	O(1)
543	Diameter of Binary Tree	diameter-of-binary-tree.cpp	O(n)	二叉树DFS	O(log(n))
554	Brick Wall	brick-wall.cpp	O(m*n)	前缀和+HashMap	O(m*n)
557	Reverse Words in a String III	reverse-words-in-a-string-iii.c	O(n)	遍历	O(n)
558	Logical OR of Two Binary Grids Represented as Quad-Trees	logical-or-of-two-binary-grids-represented-as-quad-trees.cpp	O(n)	递归	O(n)
581	Shortest Unsorted Continuous Subarray	shortest-unsorted-continuous-subarray.c	O(n)	遍历	O(1)
590	N-ary Tree Postorder Traversal	n-ary-tree-postorder-traversal.cpp	O(n)	递归/迭代	O(n)
611	Valid Triangle Number	valid-triangle-number.c	O(n^2)	双指针	O(1)
622	Design Circular Queue	design-circular-queue.cpp	O(1)	循环队列	O(n)
637	Average of Levels in Binary Tree	average-of-levels-in-binary-tree.cpp	O(n)	BFS	O(n)
640	Solve the Equation	solve-the-equation.cpp	O(n)	解一元一次方程	O(1)
643	Maximum Average Subarray I	maximum-average-subarray-i.c	O(n)	滑动窗口	O(1)
661	Image Smoother	image-smoother.cpp	O(m*n)	遍历（STL并行化）	O(m*n)
677	Map Sum Pairs	map-sum-pairs.cpp	O(n)	前缀树	O(26^n)
682	Baseball Game	baseball-game.cpp	O(n)	栈	O(n)
690	Employee Importance	employee-importance.cpp	O(n)	哈希表	O(n)
713	Subarray Product Less Than K	subarray-product-less-than-k.c	O(n)	滑动窗口	O(1)
725	Split Linked List in Parts	split-linked-list-in-parts.cpp	O(n)	求余	O(n)
729	My Calendar I	my-calendar-i.cpp	O(log(n))	借助std::map模拟平衡树	O(n)
739	Daily Temperatures	daily-temperatures.c	O(n)	单调非递增栈	O(n)
746	Min Cost Climbing Stairs	min-cost-climbing-stairs.cpp	O(n)	斐波拉契数列	O(1)
784	Letter Case Permutation	letter-case-permutation.c	O(2^n)	递归	O(2^n)
807	Max Increase to Keep City Skyline	max-increase-to-keep-city-skyline.c	O(2^n)	行列最大值	O(n)
810	Chalkboard XOR Game	chalkboard-xor-game.c	O(n)	异或	O(1)
814	Binary Tree Pruning	binary-tree-pruning.c	O(n)	递归	O(n)
816	Ambiguous Coordinates	ambiguous-coordinates.cpp		模拟
838	Push Dominoes	push-dominoes.c	O(n)	遍历	O(n)
844	Backspace String Compare	backspace-string-compare.c	O(n)	栈	O(1)
855	Exam Room	exam-room.cpp	O(log(n))	平衡树+hashMap	O(n)
861	Score After Flipping Matrix	score-after-flipping-matrix.c	O(m*n)	贪心	O(1)
863	All Nodes Distance K in Binary Tree	all-nodes-distance-k-in-binary-tree.c	O(n)	hash表+递归	O(n)
865	Smallest Subtree with all the Deepest Nodes	smallest-subtree-with-all-the-deepest-nodes.c	O(n)	递归	O(n)
869	Reordered Power of 2	reordered-power-of-2.c	O(log(n))	模拟	O(1)
870	Advantage Shuffle	advantage-shuffle.c	O(nlog(n))	田忌赛马	O(n)
876	Middle of the Linked List	middle-of-the-linked-list.cpp	O(n)	快慢指针	O(1)
881	Boats to Save People	boats-to-save-people.c	O(nlog(n))	贪心	O(1)
900	RLE Iterator	rle-iterator.c	O(n)	模拟	O(n)
947	Most Stones Removed with Same Row or Column	most-stones-removed-with-same-row-or-column.c	O(n)	并查集（路径压缩+按秩合并）	O(n)
957	Prison Cells After N Days	prison-cells-after-n-days/prison-cells-after-n-days.c	O(1)	位操作+计算周期	O(1)
967	Numbers With Same Consecutive Differences	numbers-with-same-consecutive-differences.c		DFS	O(n)
985	Sum of Even Numbers After Queries	sum-of-even-numbers-after-queries.c	O(n)	偶数运算	O(n)
991	Broken Calculator	broken-calculator.c	O(log(n))	贪心	O(1)
1006	Clumsy Factorial	clumsy-factorial.c	O(1)	数学推导	O(1)
1012	Numbers With Repeated Digits	numbers-with-repeated-digits.c	O(log10(n)^2)	组合数学	O(log10(n))
1034	Coloring A Border	coloring-a-border.c	O(m*n)	迷宫DFS	O(m*n)
1054	Distant Barcodes	distant-barcodes.c	O(n)	迷宫DFS	O(n)
1074	Number of Submatrices That Sum to Target	number-of-submatrices-that-sum-to-target.cpp	O(n^2*m)	前缀和+hash	O(m*n)
1094	Car Pooling	car-pooling.cpp	O(n)	差分数组	O(n)
1104	Path In Zigzag Labelled Binary Tree	path-in-zigzag-labelled-binary-tree.c	O(log(n))	数学推导	O(log(n))
1114	Print in Order	print-in-order.cpp	O(n)	std::promise 线程锁	O(n)
1115	Print FooBar Alternately	print-foobar-alternately.cpp	O(n)	std::atomic std::condition_variable线程锁	O(n)
1116	Print Zero Even Odd	print-zero-even-odd.cpp	O(n)		O(n)
1123	Lowest Common Ancestor of Deepest Leaves	smallest-subtree-with-all-the-deepest-nodes.c	O(n)	递归	O(n)
1129	Shortest Path with Alternating Colors	shortest-path-with-alternating-colors.cpp	O(E)	DFS最短路	O(E)
1178	Number of Valid Words for Each Puzzle	number-of-valid-words-for-each-puzzle.c	O((2^7)*n)	hashMap+位压缩	O(n)
1139	Design Underground System	design-underground-system.cpp	O(1)	双hashMap+自定义hash	O(n)
1219	Path with Maximum Gold	path-with-maximum-gold.cpp		迷宫DFS+剪枝	O(m*n)
1261	Find Elements in a Contaminated Binary Tree	find-elements-in-a-contaminated-binary-tree.c	O(log(n))	完全二叉树深度	O(1)
1333	Filter Restaurants by Vegan-Friendly, Price and Distance	filter-restaurants-by-vegan-friendly-price-and-distance.c	O(nlog(n))	排序	O(log(n))
1367	Linked List in Binary Tree	linked-list-in-binary-tree-test.c		二次递归
1379	Find a Corresponding Node of a Binary Tree in a Clone of That Tree	find-a-corr-node-of-a-binary-tree-in-a-clone-of-that-tree.cpp	O(n)	二叉树DFS	O(n)
1389	Create Target Array in the Given Order	create-target-array-in-the-given-order-test.c	O(n^2)	线性表插入	O(n)
1391	Check if There is a Valid Path in a Grid	check-if-there-is-a-valid-path-in-a-grid.c	O(m*n)	模拟	O(1)
1424	Diagonal Traverse II	diagonal-traverse-ii.cpp	O(n)	BFS	O(log(n))
1464	Maximum Product of Two Elements in an Array	maximum-product-of-two-elements-in-an-array.cpp	O(n)	遍历	O(1)
1472	Design Browser History	design-browser-history.cpp	O(1)	线性表	O(n)
1503	Last Moment Before All Ants Fall Out of a Plank	last-moment-before-all-ants-fall-out-of-a-plank.cpp	O(n)	遍历	O(1)
1636	Sort Array by Increasing Frequency	sort-array-by-increasing-frequency.c	O(nlog(n))	桶排序	O(n)
1706	Where Will the Ball Fall	where-will-the-ball-fall.cpp	O(m*n)	模拟	O(n)
1716	Calculate Money in Leetcode Bank	calculate-money-in-leetcode-bank.cpp	O(1)	等差数列求和	O(1)
1718	Construct the Lexicographically Largest Valid Sequence	construct-the-lexicographically-largest-valid-sequence.c	O(1)	DFS/打表	O(n)
1774	Closest Dessert Cost	closest-dessert-cost.c	O(n*3^m)	DFS/DP	O(n)
1763	Longest Nice Substring	longest-nice-substring.c	O(n)	滑动窗口	O(n)
1822	Sign of the Product of an Array	sign-of-the-product-of-an-array.c	O(n)	遍历	O(1)
1823	Find the Winner of the Circular Game	find-the-winner-of-the-circular-game.cpp	O(n)	DP	O(1)
1828	Queries on Number of Points Inside a Circle	queries-on-number-of-points-inside-a-circle.cpp	O(n^2)	排序+二分查找	O(n)
1833	Maximum Ice Cream Bars	maximum-ice-cream-bars.c	O(n)	贪心+桶排序	O(n)
1882	Process Tasks Using Servers	process-tasks-using-servers.cpp	O(nlog(n))	双优先队列	O(n)
1845	Seat Reservation Manager	seat-reservation-manager.cpp	O(log(n))	优先队列	O(n)
1904	The Number of Full Rounds You Have Played	the-number-of-full-rounds-you-have-played.c	O(1)	模拟	O(1)
1942	The Number of the Smallest Unoccupied Chair	the-number-of-the-smallest-unoccupied-chair.cpp	O(nlog(n))	优先队列	O(n)
2007	Find Original Array From Doubled Array	find-original-array-from-doubled-array.cpp	O(nlog(n))	排序+队列	O(n)
2043	Simple Bank System	simple-bank-system.c	O(1)	模拟	O(n)
2418	Sort the People	sort_the_people.py sort-the-people.cpp	O(n)	条件排序	O(n)
2786	Visit Array Positions to Maximize Score	visit-array-positions-to-maximize-score.cpp	O(n)	DP+状态压缩	O(1)
3084	Count Substrings Starting and Ending with Given Character	count-substrings-starting-and-ending-with-given-character.c	O(n)	排列组合	O(1)
3179	Find the N-th Value After K Seconds	find-the-n-th-value-after-k-seconds.cpp	O(1)	杨辉三角+费马小定理	O(n)
面试题 17.17	多次搜索	multi-search-lcci.c	O(m*n)	前缀树	O(m*n)

补充

• 37. Sudoku Solver 来自本人项目sudoku-solver，存在DFS和Dance Link X 两种解法，虽然DFS对简单数独（LeetCode测试样例）处理更快，但是Dance Link X在复杂数独的求解速度远远优于DFS，故采用后者。
• 76. Minimum Window Substring 若使用HashMap ，在频繁调用时候性能欠佳，因题目给出key仅为英文字母，所以采用了固定数组来统计出现次数。
• 84. Largest Rectangle in Histogram 借助单调栈实现O(n) 算法，且已尽可能优化。但是测试样例存在bug ，即使使用提交页面提供的0ms代码，在当前测试样例下，至少也有80ms耗时，与本人结果一致，怀疑存在后期加入其他复杂测试样例。
• 89. Gray Code 已做到时间+空间最优解，运算全部位运算，不论golang还是C++都做不到0ms解或则最优空间解。
• 147. Insertion Sort List 要求在单链表上实现插入排序（时间复杂度：O(n^2)，空间：O(1)），但为了在线评测中时间表现优异，添加了快速排序实现（时间复杂度：O(nlog(n))，空间：O(n)）。
• 149. Max Points on a Line 有三点枚举优化和斜率HashMap两种方法，前者在本地性能测试中总优于后者，但在线测试时前者耗时均多于后者。
• 172. Factorial Trailing Zeroes 要求统计阶乘末尾0的个数，解法是计算阶乘中质因子5的个数，时间复杂度O(log_5(n))。又因为数据范围小，通过循环展开，实现理论时间复杂度O(1)。
• 187. Repeated DNA Sequences 使用双HashSet来统计结果，因为key值过多，存在性能问题。
• 295. Find Median from Data Stream 使用双优先队列实现，已做尽可能优化逻辑，与提交页面最优解基本一致，但时间不能做到最快，怀疑后期加入复杂用例。
• 224. Basic Calculator 和 227. Basic Calculator II 解法来自本人项目str_expr_eval，实现：字符串表达式 → 中缀表达式 → 后缀表达式 → 求值 流程，由于更具泛用性，需要额外的线性时间处理和额外的线性空间记录中间值，难以实现时间和空间优势，但复杂度上不变。
• 1774. Closest Dessert Cost 存在DFS或则DP两种解法，后者在时间复杂度上更优，但由于本题数据量小，在极限数据上DFS方法耗时小于DP方法耗时，故采用DFS方法。
• 406. Queue Reconstruction by Height 插入操作可以使用线段树优化，待后续补充。